Back in 1971, the square-jawed, clean-cut decorated combat veteran, with a generous mop of dark hair, told a rapt audience of senators of atrocities he said had been reported to him by his fellow soldiers in Vietnam.

Rapes. Razed villages. Ears and heads cut off. Random shootings of civilians. Bodies blown up. Wires from portable telephones taped to genitals, with the power then turned on. Food stocks poisoned. Dogs and cats shot for the fun of it.

"We wish that a merciful God could wipe away our own memories of that service as easily as this administration has wiped their memories," Kerry told members of the Senate Foreign Relations Committee in testimony that made him a national figure at 27.

To those who were against the war, he was a courageous hero standing up for the truth; to those who supported it, he was a treasonous pariah aiding the enemy.

But no matter how his words were viewed, their power was beyond question. Even President Nixon groused about him in the Oval Office.

"John was able to speak to people, whether they were conservative or liberal, Democrat or Republican, and people listened," said Lenny Rotman, who worked with Kerry back then in the group Vietnam Veterans Against the War.

Today, more than three decades after making those charges, Kerry is the presumptive Democratic presidential nominee, fighting a close campaign during a time of war, putting his resume as a Vietnam hero front and center.

At 60, the hair is graying, though the jaw is still square. And he is still explaining and defending those strong, vivid words, which continue to divide.

"I think the way I characterized it at that time was mostly the voice of a young, angry person who wanted to end the war," Kerry told CNN's Candy Crowley in an interview broadcast on Thursday's anniversary of his Senate testimony.

"I regret any feeling that anybody had that I somehow didn't embrace the quality of the service. But I have always said how nobly I think every veteran served."

The senator concedes he wouldn't say the same things in the same way today, that talk of "atrocities" back then was over the top. Yet, he insists he's still proud he stood up against the war. While he has regret for the words he chose, he defends the legitimacy of the sentiment he so starkly articulated.

"They were honest expressions of the passion that we brought to the cause," said Kerry. "I'm older, I'm wiser. I'm farther from it. But they were the words that came out of my gut at that time, based on the anger and frustration that I felt back when it was happening."

He also told Crowley, "I'm not going to back down one inch on what I've fought for and what I've stood for all of these years."

Such qualified regret doesn't go far enough for some Vietnam veterans, who can't forgive the stigma they still see attached to those long-ago words.

"He was the father of the lie that the Vietnam veteran was a rapist, a baby killer, a drug addict and the like," said John O'Neill, who served in the same Navy patrol unit where Kerry served and who sparred with him on national TV during the tumult of 1971. "I don't think there's anybody that did that, or created that, more than Kerry." (Fellow vet blasts Kerry's antiwar comments)

Kerry bristled at the suggestion that he ever said Vietnam soldiers were baby killers.

"I never said baby killing," he told Crowley. "I fought that image everywhere I went. .... I described accurately what was happening, and what wasn't."

The senator also said the negative image of the Vietnam veteran didn't start with him -- and that his anger was directed not at the soldiers who served but at the people who sent them "to die for the biggest nothing in history," as he put it in 1971.

"I came back to find Americans who were unwilling to welcome us home, who spat on veterans when they came home. I didn't start that," he said. "All I did was to tell the truth about some of the things that happened over there."

"I never put the load on soldiers. I asked, 'Where's the leadership of the country?' not the soldiers," he said. "All I know is that it happened as a matter of course, and there were things that were happening over there as a matter of policy."

Looking back, Kerry said he was young, he was angry and he wanted the war to end.

"The legitimacy of what we observed and saw and were fighting for, I wouldn't change at all. That was important. And it was generationally important, and I stand by that."